The book illustrates the wide range of design styles that the same architects or their firms employed during the course of their careers pre-1948. The notable exception were those architects who worked in, or expanded the Georgian/Federal style—Peter Harrison, Charles, Bulfinch, Asher Benjamin and Alexander Parris—and the two exceptions, H. H. Richardson and McKim, Mead & White. The exploration of the buildings by the architects and firms listed was limited to "Northern Boston" as defined by the National Register of Historic Places—encompassing those locations in the city that are located north of the Massachusetts Turnpike. The book was written during the COVID-19 Pandemic so all the information compiled therein was from on-line sources.